Table 1.

Means and Standard Deviations for Study Variables (N = 530)

Variable	M	SD
Independent/treatment variable
Heavy adolescent marijuana use (0 = use less than 20 times or no use, 1 = use 20 times or more)	0.258	0.438
Matching variable
Gender (0 = female, 1 = male)	0.470	0.500
Mother’s history of drug use (0 = no illicit drug use, 1 = illicit drug use)	0.030	0.171
Mother’s years of schooling	10.606	2.298
Family income for 1965–1966 (1 = under $2,000, 10 = $10,000 or more)	4.902	2.749
Below poverty threshold (0 = above the poverty threshold, 1 = below the poverty threshold)	0.491	0.500
First-grade classroom adaptation (0 = adapting, 3 = severely maladapting)
Teacher rating of underachievement	0.596	0.922
Teacher rating of aggression	0.474	0.861
Teacher rating of shyness	0.457	0.820
Teacher rating of immaturity	0.562	0.921
Teacher rating of inattention	0.532	0.934
Outcome variable
Employed at age 32–33 (0 = unemployed, 1 = employed)	0.647	0.478
Married at age 32–33 (0 = unmarried, 1 = married)	0.292	0.455
Teen parent (0 = not a teen parent, 1 = teen parent)	0.266	0.442
Parenting outside of marriage (0 = no parenting outside of marriage, 1 = parenting outside of marriage)	0.538	0.499
Mediator
High school dropout (0 = diploma/GED, 1 = high school drop out)	0.175	0.381
Adult marijuana use at age 32–33 (0 = no use, 1 = past year use)	0.194	0.396

Note. GED = general equivalency diploma.